MTECHTIPS- Oil futures finished slightly higher on Friday, logging their fourth weekly gain in a row with traders encouraged by signs that major crude producers will adhere to the pledge to curb output. On the New York Mercantile Exchange, crude oil for delivery in February inched up 23 cents, or about 0.4%, to end at $53.99 a barrel by close of trade Friday. U.S. crude prices touched an 18-month high of $55.24 on Tuesday. For the week, New York-traded oil futures added 97 cents, or about 1.8%, after posting gains in each of the previous three weeks. Elsewhere, on the ICE Futures Exchange in London, Brent oil for March delivery tacked on 21 cents, or nearly 0.4%, to settle at $56.82 a barrel by close of trade. Brent prices rallied to $58.37 on Tuesday, a level not seen since July 2015. London-traded Brent futures logged a gain of 28 cents, or approximately 0.5%, on the week. Prices tallied a weekly gain amid signals that major oil producers, such as Saudi Arabia and Kuwait, are sticking to their pledge to cut back output. January 1 marked the official start of the deal agreed by OPEC and non-OPEC member countries such as Russia in November last year to reduce output by almost 1.8 million barrels per day.