Gap Third-Quarter Earnings Tick Up 1 Pct  NEW YORK (Reuters) - Clothing retailer Gap Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=GPS.N target=/stocks/quickinfo/fullquote"&gt;GPS.N&lt;/A&gt;  said on Thursday its third-quarter earnings ticked up 1  percent, hemmed in by lackluster sales at its Old Navy and   international Gap stores open at least a year.