The company acquired the Knorr-branded sauce products in 2000, following its merger with Bestfoods.
The move follows chief executive Paul Polman's decision that there is little growth left for the brands in the UK. Neither of the brands is among the company’s best sellers here. The FMCG company is to retain the Ragu brand outside the UK.
It is understood that Unilever is looking to find a trade or private equity buyer for the brands.
Premier Foods, which owns sauce brands including Loyd Grossman and Sharwoods, is not thought to be in the running because of its significant debt pile.
Other interested parties could include Domio owner Mars Foods.
The sale of the brands could net Unilever up to £40m, according to The Times.
The development follows Unilever agreeing to a $3.7bn deal this week to buy Alberto Culver, which owns haircare brands VO5 and Tresemmé.
A spokesman for Unilever said: "Unilever UK and Ireland is assessing its strategic options for our Chicken Tonight and Ragu brands.
"We regularly evaluate the performance of our brands in the marketplace and we will consider all options when reviewing their future. It is business as usual while this review takes place."