I think that redlining is done more for the business benefits for banks rather than an attempt to be racist. It ends up being racist because it generally tells banks to avoid poorer areas, which consequently are generally filled with minority groups. Redlining is racist, but I don't think it is intended to be.
Redlining may or may not be intended to target racial groups, but it usually ends up targeting them anyway. The means of production are owned by a very small minority of people in the nation, and if they (I mean banks and insurance for example) refuse to invest in an area then the people are limited in what they can do, unless they take matters into their own hands, which civil government tends to fight against.
Redlining is the process of charging more for or limiting access to services such as banking, health care, jobs or even shopping malls to the residents of particular areas, which are typically determined by the racial makeup of the area in question. Redlining serves no legitimate function except to punished the members of a particular race or ethnic group.
Everyone is out to protect their own interests, and banks so charge higher rates for high risk investments in loans, real estate and other ventures.
If a section of neighborhood tends to have higher losses, more defaults, or people have lower income, they are considered high risk and are given less favorable terms.
The true question is why more people of ethnic origin fall into these groups.
If something is not done with racist intentions, it is not racist. Racism is an "ism," meaning it is an ideology or set of beliefs, in particular about race. If redlining does not come from a racist worldview, then it is not racist, regardless of results. Poor neighborhoods are a bad investment for banks, but this doesn't mean that black neighborhoods are, to use an American example. Of course, in the US, black neighborhoods are disproportionately poor, which causes many to believe that redlining policies may hide white supremacist intentions. This has yet to be proven. All evidence points to bankers' self-interest, rather than racial discrimination.
Redlining is often a racist practice, and used as a way to avoid doing business with people of certain races without really saying that that's what you're doing. However, there's nothing about the basic idea of it that is racist, and it can be used in non-racist ways. These may be discriminatory in other ways, though.