Specialty retailer Gap Inc has parted ways with its design chief Patrick Robinson as it tries to dig its business out of a long-time rut of falling sales and clothes that continue to miss the mark.

"After spending the last three months in New York with the creative team, I've made the decision to make a change within our Gap Adult design team," Pam Wallack, head of the Gap Global Creative Center in New York, admitted today (5 May).

The company said it will begin a search immediately for Robinson's replacement.

In the interim, Wallack will provide day-to-day management of the design teams, and has asked Jennifer Giangualano, senior vice president of kids and baby design, to oversee adult design during this transition period.

Rosella Giuliani, who heads the brand's design office in Los Angeles, will continue to oversee Gap's 1969 denim product line, reporting directly to Wallack.

"Our leaders of the new Gap Global Creative Center are taking the necessary steps to compete and win around the world," added chairman and CEO Glenn Murphy.

Robinson, who joined San Francisco based firm in May 2007 as executive vice president of Gap Global Design for Adult and Body, was seen as a good choice to help lift the US clothing giant out of the doldrums.

Having put his mark on fashions ranging from Target to Giorgio Armani, Paco Rabanne, Perry Ellis and Anne Klein, his broad experience from high-end fashion to mass market retail was considered key to helping the Gap brand reinvigorate its designs.

But now, after a five-year run of declining same-store sales, the retailer is taking major steps to try to shake up its business - particularly its North American namesake division.

While the firm recently delivered a 9.3% rise in full-year earnings to $1.2bn, and a 3.3% rise in revenues to $14.7bn, Gap's North American division was the only unit to report negative same-store sales for the full year, down 1%.

In February it introduced a raft of changes to its North American management team, replacing president Marka Hansen with Art Peck, former head of the outlet division, as the unit's boss.

It has also set up a Global Creative Center in New York to improve performance and execute one global design vision for Gap brand around the world.

And last month plans were revealed to consolidate its international operations into one unit based in London as part of a major push to grow its business globally - including opening its first overseas Old Navy store next year.

But earlier this year Murphy told analysts that "consistently, by season, we're still not there" with products that customers want to buy.

Robinson's efforts to include more fashion in the line-up scored some hits such as the revamped 1969 denim line, but there have been major misses too, especially in women's tops.

"Our goal has to be, and it's non-negotiable, to get consistent product in all three of our North American brands, but at particularly Gap North America," Murphy says. "When we're good, we're good. But being good two-thirds of the time, in this environment, with this new consumer is not going to deliver what we want."