FinnCap has maintained its sell rating on oil giant Tullow after its production figures again missed targets.The firm said that production for 2011 averaged 78.2 thousand barrels of oil equivalents per day (mboepd), slightly below the (already revised lower) guidance of 79-81mboepd and the 80.4mboepd that finnCap was expecting. Guidance for 2012 is 78-86mboepd, well under the broker's previous forecast of 98.6mboepd."Tullow again reported weaker than expected production as the company struggles with both declining volumes at mature fields and problems at Jubilee, and these issues look set to continue into 2012," said analyst Will Arnstein.While the group financials seem to be in line, finnCap says that the upside potential for Tullow is "less than is available elsewhere in the sector".A 1,000p target price is retained.The update wasn't taken well by the markets on Wednesday, which marked the shares down 7.01% at 1,353p in mid-morning trade.BC